RESUMEN

DNA methylation is an important component of the epigenetic machinery and plays a critical role in transcriptional regulation. It mostly occurs in CpG abundant regions, known as CpG islands (CGIs). G protein-coupled receptor 120 (GPR120) functions as an omega-3 fatty acid receptor and is involved in multiple-biological processes, including lipogenesis. Herein, we show that GPR120 is highly expressed in porcine mature adipose tissue and is positively associated with adipose tissue development (r = 0.86, P < 0.01). We also predicted 5 CGIs across the GPR120 genomic sequence and investigated their methylation status using the MassArray approach. Our results show that these CGIs exhibit significantly different methylation states (P(CGI) < 0.01), and that the DNA methylation of GPR120 5ꞌ-untranslated and first exon regions can negatively regulate its expression levels. This study will aid further investigations on the epigenetic mechanism regulating GPR120 expression.

Asunto(s)

Tejido Adiposo/metabolismo , Islas de CpG , Metilación de ADN , Epigénesis Genética , Receptores Acoplados a Proteínas G/genética , Sus scrofa/metabolismo , Adipogénesis , Tejido Adiposo/fisiología , Animales , Femenino , Regulación del Desarrollo de la Expresión Génica , Sus scrofa/genética , Sus scrofa/fisiología

RESUMEN

The myosin heavy chain (MyHC) composition, glycolytic potential, mitochondrial content, and gene expression related to energy metabolism were analyzed in eight muscles from Tibetan pigs, to study how meat quality develops in different muscle tissues. The muscles were classified into three clusters, based on MyHC composition: masseter, trapezius, and latissimus dorsi as 'slow-oxidative-type'; psoas major and semimembranosus as 'intermediate-type'; and longissimus dorsi, obliquus externus abdominis, and semitendinosus as 'fast-glycolytic-type'. The 'slow-oxidative-type' muscles had the highest MyHC I and MyHC IIA content (P < 0.01); 'intermediate-type' muscles, the highest MyHC IIx content (P < 0.01); and 'fast-glycolytic-type' muscles, the highest MyHC IIb content (P < 0.01). The pH values measured in 'slow-oxidative-type' muscles were higher than those in the other clusters were; however, the color of 'fast-glycolytic-type' muscles was palest (P < 0.01). Mitochondrial content increased in the order: fast-glycolytic-type < intermediate-type < slow-oxidative-type. In the 'slow-oxidative-type' muscles, the expression levels of genes related to ATP synthesis were higher, but were lower for those related to glycogen synthesis and glycolysis. Mitochondrial content was significantly positively correlated with MyHC I content, but negatively correlated with MyHC IIb content. MyHC I and mitochondrial content were both negatively correlated with glycolytic potential. Overall, muscles used frequently in exercise had a higher proportion of type I fibers. 'Slow-oxidative-type' muscles, rich in type I fibers with higher mitochondrial and lower glycogen and glucose contents, had a higher ATP synthesis efficiency and lower glycolytic capacity, which contributed to their superior meat quality.

Asunto(s)

Glucólisis/genética , Carne , Fibras Musculares Esqueléticas/metabolismo , Cadenas Pesadas de Miosina/biosíntesis , Miosina Tipo IIB no Muscular/biosíntesis , Adenosina Trifosfato/metabolismo , Animales , Metabolismo Energético/genética , Regulación de la Expresión Génica , Glucógeno/metabolismo , Mitocondrias/genética , Mitocondrias/metabolismo , Cadenas Pesadas de Miosina/genética , Miosina Tipo IIB no Muscular/genética , Porcinos

RESUMEN

DNA methylation is a stable epigenetic mark mediating gene expression. Methylation is crucial for diverse biological processes, including aging and embryo development. FASN (fatty acid synthase) plays an important role in de novo lipogenesis, through catalyzing the reductive synthesis of long-chain fatty acids. In this study, we investigated the FASN gene expression pattern and corresponding DNA methylation status in the inner layer of backfat from Jinhua pigs at different developmental stages. Our results showed that FASN gene expression increases with age and is positively associated with adipocyte volume (r = 0.98, P < 0.01). In addition, the DNA methylation level for the first exon (0.11, CGI 3) of the FASN gene is approximately 8-fold lower than levels for its promoter (0.94, CGI 1&2) (two-way ANOVA, PCGI < 0.01). The association analysis revealed that both promoter (r = -0.944, P < 0.01) and first exon methylation (r = -0.774, P < 0.01) are significantly and negatively correlated with FASN gene expression. Our results will benefit future investigations of the epigenetic mechanism underlying FASN gene expression.

Asunto(s)

Metilación de ADN , Exones , Acido Graso Sintasa Tipo I/genética , Porcinos/genética , Tejido Adiposo , Animales , Epigenómica , Ácidos Grasos/genética , Regulación de la Expresión Génica , Lipogénesis , Regiones Promotoras Genéticas

RESUMEN

The aim of this study was to analyze the results of two crossing systems between wild boars and different domesticated pig breeds. Hybrid wild boars were produced by crossing captured wild boars with Meishan pigs and LY sows according to the traditional production system. The resultant commercial hybrids were black and white in coat color, respectively. Significant differences were found in the carcass and meat quality traits and nutritional values between these two hybrid wild boars. Compared with the white hybrid wild boars, at the age of 300 days, the body weight of black hybrid wild boars was 9.41 kg lower, while percent lean was 2.51% less and percent fat 2.45% higher (P < 0.05). The black hybrid wild boars had higher pH2 (6.17 vs 6.09) and intramuscular fat (3.34 vs 2.52%), lower drip loss (2.21 vs 2.68%) and shear force (44.00 vs 52.23) (P < 0.05), and more unsaturated fatty acids and essential amino acids (P < 0.05). In conclusion, cross breeding was shown to be an effective method to improve the overall production performance of wild boars, but crossing with different dam line breeds caused different responses. Compared with the white hybrid wild boars, the black hybrid wild boars had worse growth rate and carcass traits, but better meat quality traits and nutritional values.

Asunto(s)

Peso Corporal/genética , Hibridación Genética , Carne/análisis , Valor Nutritivo , Sus scrofa/genética , Tejido Adiposo/metabolismo , Aminoácidos Esenciales/metabolismo , Animales , Composición Corporal/genética , Cruzamiento/métodos , Cruzamientos Genéticos , Ácidos Grasos Insaturados/metabolismo , Femenino , Color del Cabello/genética , Masculino , Carne/normas , Sitios de Carácter Cuantitativo/genética , Porcinos

RESUMEN

Mitochondrial DNA (mtDNA) content is dependent on the energy requirements of tissues. To date, no comprehensive study has been conducted to examine mtDNA copy number variations in pigs. In the current study, quantitative polymerase chain reaction was performed to quantify the mtDNA copy number in 15 pig tissue types at 5 growth stages from embryo to adult. Observable differences in mtDNA content were detected in the tissues, including a 6-fold greater mtDNA content in the heart compared with the lung of 180-day-old samples. mtDNA content in the heart, longissimus dorsi muscle, psoas major muscle, kidney, brain, ovary, and subcutaneous adipose increased with growth. Expression of the replicative mitochondrial helicase (TWINKLE), which regulates mtDNA turnover, was significantly associated with changes in mtDNA copy numbers across tissues during growth (r = 0.33, P = 0.01). We demonstrated that the expression levels of mitochondrial genes were positively correlated with mtDNA copy number.

Asunto(s)

Variaciones en el Número de Copia de ADN , ADN Mitocondrial/genética , Porcinos/genética , Tejido Adiposo/embriología , Tejido Adiposo/crecimiento & desarrollo , Animales , Encéfalo/embriología , Encéfalo/crecimiento & desarrollo , ADN Helicasas/genética , ADN Helicasas/metabolismo , Femenino , Riñón/embriología , Riñón/crecimiento & desarrollo , Mitocondrias/genética , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Músculo Esquelético/embriología , Músculo Esquelético/crecimiento & desarrollo , Ovario/embriología , Ovario/crecimiento & desarrollo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Porcinos/embriología , Porcinos/crecimiento & desarrollo

RESUMEN

Parentage analysis and individual identification are recent, promising methods that have been applied to evolutionary and ecological studies, as well as conservation management. Parental exclusion relying on polymorphic microsatellites has been used worldwide in parentage determination, while the low mutation rate and genotyping error rate of single nucleotide polymorphisms (SNPs) make them another important marker for pedigree tracing. Here, we compared the effectiveness of microsatellites and SNP markers in European pigs. We also measured and presented the minimum and optimal criteria for SNP markers to be used in paternity and identity analysis. Our findings may contribute to the development of techniques for future molecular evolution and conservation studies, as well as breeding programs.

Asunto(s)

Repeticiones de Microsatélite/genética , Polimorfismo de Nucleótido Simple , Sus scrofa/genética , Animales , Cruzamiento , Europa (Continente) , Femenino , Frecuencia de los Genes , Genotipo , Masculino , Modelos Genéticos , Linaje , Probabilidad , Análisis de Secuencia de ADN

RESUMEN

Muscle growth and development is associated with remarkable changes in protein-coding and microRNA (miRNA) gene expression. To determine the expression patterns of genes and miRNAs related to muscle growth and development, we measured the expression levels of 25 protein-coding and 16 miRNA genes in skeletal and cardiac muscles throughout 5 developmental stages by quantitative reverse transcription-polymerase chain reaction. The Short Time-Series Expression Miner (STEM) software clustering results showed that growth-related genes were downregulated at all developmental stages in both the psoas major and longissimus dorsi muscles, indicating their involvement in early developmental stages. Furthermore, genes related to muscle atrophy, such as forkhead box 1 and muscle ring finger, showed unregulated expression with increasing age, suggesting a decrease in protein synthesis during the later stages of skeletal muscle development. We found that development of the cardiac muscle was a complex process in which growth-related genes were highly expressed during embryonic development, but they did not show uniform postnatal expression patterns. Moreover, the expression level of miR-499, which enhances the expression of the ß-myosin heavy chain, was significantly different in the psoas major and longissimus dorsi muscles, suggesting the involvement of miR-499 in the determination of skeletal muscle fiber types. We also performed correlation analyses of messenger RNA and miRNA expression. We found negative relationships between miR-486 and forkhead box 1, and miR-133a and serum response factor at all developmental stages, suggesting that forkhead box 1 and serum response factor are potential targets of miR-486 and miR-133a, respectively.

Asunto(s)

Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , MicroARNs/genética , Desarrollo de Músculos/genética , Sistemas de Lectura Abierta/genética , Sus scrofa/crecimiento & desarrollo , Sus scrofa/genética , Animales , Análisis por Conglomerados , Femenino , MicroARNs/metabolismo , Cadenas Pesadas de Miosina/genética , Cadenas Pesadas de Miosina/metabolismo , Programas Informáticos

RESUMEN

Here, we analyzed the distribution of H-FABP/(HinfI, MspI, and HaeIII) and ACSL4/RsaI polymorphisms, and the associations of these 4 polymorphic loci with intramuscular fat (IMF) content and backfat thickness (BFT) in Yanan, Jinhua, Duroc, Landrace, Yorkshire, and Duroc x (Landrace x Yorkshire) (DLY) pigs. H-FABP/HinfI polymorphisms were present in all the 6 populations. At the ACSL4/RsaI locus, sows had 3 genotypes, whereas boars only had haplotype A or G, in Duroc, Landrace, Yorkshire, and DLY pigs. H-FABP/(MspI and HaeIII) and ACSL4/RsaI polymorphisms were absent in Yanan and Jinhua pigs. Linkage disequilibrium analysis indicated that the 3 loci (HinfI, MspI, and HaeIII) were separated. Association analysis showed that the H-FABP/HinfI locus significantly affected IMF content in DLY (P < 0.05) and Yanan (P < 0.001) pigs. The highest IMF content was recorded in the adH haplotype of the 3 H-FABP polymorphic loci (2.59%, P < 0.05) in DLY pigs. At the ACSL4/RsaI locus, higher IMF content was recorded for sows with a GG genotype or boars with a G haplotype compared to those with an AA genotype (2.53 vs 2.10%, P < 0.05) or A haplotype (2.48 vs 1.73%, P < 0.01) in DLY pigs. Significant differences were not obtained among these 4 polymorphic loci and BFT (P > 0.05). The results indicate that H-FABP and ACSL4 genes might serve as markers to improve IMF content (but not BFT) in the pig breeding system.

Asunto(s)

Tejido Adiposo/metabolismo , Coenzima A Ligasas/genética , Proteínas de Unión a Ácidos Grasos/genética , Polimorfismo Genético , Alelos , Animales , Femenino , Frecuencia de los Genes , Genética de Población/métodos , Genotipo , Haplotipos , Desequilibrio de Ligamiento , Masculino , Músculos/metabolismo , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Porcinos

RESUMEN

The balance between biosynthesis and oxidation of fatty acids determines adipose deposition in mammals. Obese and lean pigs show obvious differences in total adipose mass and therefore offer an attractive model for comparative studies. We found that obese Rongchang pigs, when compared with lean Landrace pigs, exhibited significantly higher mRNA levels for five genes encoding acyl-CoA dehydrogenases involved in mitochondrial fatty-acid ß-oxidation in eight different adipose tissues. These changes in gene expression were positively correlated with adipocyte volume in the eight adipose tissues. Based on these results, we hypothesize that acyl-CoA dehydrogenase genes participate in the regulation of fat mass in pigs.

Asunto(s)

Acil-CoA Deshidrogenasas/biosíntesis , Tejido Adiposo/enzimología , Obesidad/genética , Acil-CoA Deshidrogenasas/genética , Adipocitos/metabolismo , Animales , Cruzamiento , Ácidos Grasos/metabolismo , Regulación de la Expresión Génica , Obesidad/veterinaria , Oxidación-Reducción , ARN Mensajero/genética , Sus scrofa/genética , Porcinos/genética , Porcinos/crecimiento & desarrollo

RESUMEN

This study analyzed the effect of muscle-fiber type composition on glycogenin-1 (GYG) gene expression and its impact on pH. The longissimus dorsi (LD) muscle contains more type IIB fibers (75.10%) than does the psoas major (PM) muscle (41.58%), while the PM has more type I (3.65 vs 0.94%), type IIA (34.15 vs 10.63%), and type IIX (20.62 vs 13.33%) fibers. Compared with PM, glycolytic potential (GP), pH45 min, and ΔpH from 45 min to 24 h post-mortem were all relatively higher in LD. Glycogen metabolites (lactate and GP) were negatively correlated with pH24 h and positively correlated with ΔpH. Expression of GYG was generally higher in LD. GYG expression was positively correlated with glycogen metabolite (lactate and GP) content and ΔpH, and was negatively correlated with pH24 h. These data confirm that the muscle-fiber type and GP have significant effects on ultimate pH and pH decline, and suggest that expression of GYG in muscles is related to the metabolism of glycogen and may impact GP, ΔpH, and ultimate pH. High expression of GYG was associated with a high glycogen content, large pH decline, and low ultimate pH in muscles post-mortem.

Asunto(s)

Glucosiltransferasas/biosíntesis , Glucógeno/metabolismo , Glicoproteínas/biosíntesis , Fibras Musculares Esqueléticas/metabolismo , Porcinos/genética , Animales , Regulación de la Expresión Génica , Glucosiltransferasas/genética , Glicoproteínas/genética , Concentración de Iones de Hidrógeno , Masculino , Carne , Fibras Musculares Esqueléticas/clasificación , Porcinos/crecimiento & desarrollo

RESUMEN

DNA methylation may be involved in regulating the expression of protein-coding genes, resulting in different fat and muscle phenotypes. Using a methylation-sensitive amplified polymorphism approach, we obtained 7423 bands by selective amplification of genomic DNA from six different fat depots and two heterogeneous muscle types from Duroc/Landrace/Yorkshire cross-bred pigs. The degrees of DNA methylation, determined by the percentages of hemi- and fully methylated sites relative to the total number of CCGG sites, were similar in male and female pigs for each specific tissue [χ(2) test; P (two-tailed) > 0.05]. Gender bias was therefore ignored. There were significant differences in the degree of DNA methylation among the eight tissue types [χ(2) test; P(total) (two-tailed) = 0.009]. However, similar degrees of methylation were observed among the six fat depots [χ(2) test; P(fat) (two-tailed) = 0.24 > 0.05]and between the two muscle types [χ(2) test; P(muscle) (two-tailed) = 0.76 > 0.05]. We conclude that the degree of DNA methylation differs between porcine fat and muscle tissue, but that the methylation status of a particular tissue type is similar, despite being deposited at different body sites.

Asunto(s)

Adiposidad/genética , Metilación de ADN/genética , Músculos/metabolismo , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Sus scrofa/genética , Animales , Femenino , Masculino , Especificidad de Órganos/genética

RESUMEN

We evaluated carcass and meat quality traits of two Chinese native crossbreeds Landrace x Meishan (LM) and Duroc x (Landrace x Meishan) (DLM) and two foreign crossbreeds Duroc x (Landrace x Yorkshire) (DLY) and PIC (an imported five-way crossbreed). One hundred and twenty weaned pigs (half castrated males and half females) were reared and slaughtered at a predestinated slaughter age. The general carcass and meat quality traits were measured and analyzed. The DLY and PIC crosses had significantly heavier live weights (93.39 and 96.33 kg, P < 0.01), significantly higher dressing percentages (80.65 and 79.39%, P < 0.05), significantly bigger loin areas (42.69 and 43.91 cm(2), P < 0.001), and significantly more lean carcasses (65.78 and 66.40%, P < 0.001) than LM and DLM. On the other hand, LM had a significantly lower live weight (70.29 kg, P < 0.01), significantly thicker back fat (3.54 cm, P < 0.001), significantly less lean carcasses (46.82%, P < 0.001), and significantly less ham and breech (26.53%, P < 0.05) than the other crossbreeds. Among meat quality parameters, LM had the highest intramuscular fat content (5.02%, P < 0.001) and the smallest fiber area (3126.45 µm(2), P < 0.01). However, PIC showed the lowest pH(1) (5.82, P < 0.01) and pH(2) (5.63, P < 0.01), the highest drip loss (2.89%, P < 0.01), and the lowest intramuscular fat (1.35%, P < 0.001). We concluded that LM and DLM had good meat quality traits but poorer carcass traits than DLY and PIC; DLY had good carcass and meat quality traits; PIC had good carcass traits, but it had less intramuscular fat, lower pH and higher drip loss.

Asunto(s)

Calidad de los Alimentos , Carne/normas , Animales , Composición Corporal , Peso Corporal , China , Femenino , Hibridación Genética , Masculino , Músculo Esquelético/anatomía & histología , Grasa Subcutánea/anatomía & histología , Sus scrofa/anatomía & histología , Sus scrofa/genética

RESUMEN

Malate dehydrogenases 1 and 2 (MDH1 and MDH2), and malic enzyme 1 (ME1) play important roles in the Krebs cycle for energy metabolism. The mRNA abundance changes of MDH1, MDH2 and ME1 genes were measured across six different adipose tissues from the leaner Landrace and fatty Rongchang pig breeds using quantitative real-time PCR. The mRNA of MDH1, MDH2 and ME1 was more abundant in fatty Rongchang pigs than in leaner Landrace pigs. In both breeds, females exhibited higher adipocyte volume and mRNA abundance of MDH1, MDH2 and ME1 compared with males. These values were higher in the subcutaneous adipose tissue compared with visceral adipose tissue. Furthermore, mRNA abundance changes of MDH1, MDH2 and ME1 have the remarked significant positive correlation with adipocyte volume across the six adipose tissue types. We conclude that there are breed-, gender- and tissue-specific expression patterns of ME1, MDH1 and MDH2, which highlight their potential as candidate genes for selecting for fat volume in pigs.

Asunto(s)

Tejido Adiposo/metabolismo , Isoenzimas/genética , Malato Deshidrogenasa/genética , Animales , Secuencia de Bases , Cartilla de ADN , Femenino , Masculino , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Porcinos